alamb commented on issue #3620: URL: https://github.com/apache/arrow-rs/issues/3620#issuecomment-1591262673
> A value not being in the selection mask implies it is going to be discarded regardless of the output of the current kernel. I'm therefore not sure why it would ever matter? What am I missing here? Correct -- I thought you were asking if there were semantic differences between a selection vector and a null mask and so I was providing an example where there would be. I probably misunderstood this: > This then leads to the obvious question, if a false value in a selection vector indicates that the result doesn't matter, how would the semantics of an operation under a selection vector differ from the semantics of an operation with the arrays first passed to [nullif](https://docs.rs/arrow-select/latest/arrow_select/nullif/fn.nullif.html) with the selection vector. As the result is irrelevant, why would its null-ness matter? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
